1. Field of the Invention
The present invention relates to an automatic carrier system using a plurality of carrier means to automatically carry objects between optional regions and to an automatic carrying method using this automatic carrier system.
2. Description of Related Art
FIG. 1 is a structural plan view of the conventional automatic carrier system, in which reference numerals 3 designate production regions formed by collecting the same kinds of production facilities, and the production regions 3 are disposed in two parallel rows spaced at a predetermined interval. Between the rows of the production regions 3 is provided a track 41 circulating along the production regions 3 in a flat circular manner when planar-viewed. The track 41 is provided above the production regions 3 (or underground) in order to improve work efficiency. On the track 41 are disposed a plurality of carriers 42 circulating along the track 41 in the predetermined direction. Each production region 3 is provided with a delivery unit 32 for delivering the object between each production region 3 and each carrier 42. The carriers 42, when carrying the objects, are adapted to stop in front of the delivery unit 32 at a desired production region 3.
Next, explanation will be given on operation of the automatic carrier system. In a case that the object is carried between the desired production regions 3, the object is carried to the delivery unit 32 at the production regions 3 and it is lifted (or lowered) to the track 41 and transferred to the carrier 42 by the delivery unit 32. The carrier 42 moves toward the delivery unit 32 of the production region 3 to which the object is to be carried, and transfers the object to the delivery unit 32, so that the object is lowered (or lifted) by the delivery unit 32 onto which the object is transferred and it is delivered by a dolly from the delivery unit 32 to the production facility of the production region 3 to which the object is to be carried.
However, the above-mentioned conventional automatic carrier system carries the objects between the production regions 3 entirely through the track 41. Accordingly, the carrying amount by using the carriers 42 is large and there is a fear that the carrying amount exceeds the carrier capacity of each carrier 42, thereby creating the problem that many objects waiting to be carried remain and the number of unfinished objects increases to extend a manufacturing period.